I'm not 100% on US purchases, but I believe people in some (but not all) states can buy without any significant sales tax from out of state. Plus, given this is software, the physical side isn't essential. If you have a suitable friend over there, get them to buy it, transfer the data digitally with the serial/key.
You can download the "trial" software directly from Adobe's website then just input the serial key.
In the states you can always avoid sales tax if you order from a retailer out of state and just pay a minimum shipping charge.. So long as the retailer does not operate in your state you won't be charged a sales tax.